This reality is considered very different from many other alternate realities in the Marvel Multiverse because it does not differ as extremely as many others, rather it is simply a reversal of the status of Homo Sapiens Sapiens and Homo Superior in the world.

Beginning

This change of status quo began in 1979 when Magneto was attacked by Sentinels above Manhattan. As the fight came to an end, Magneto revealed an international conspiracy against mutants, involving Richard Nixon. So it was that Magneto was granted sovereignty over Genosha, and became the leader of the world's mutants.

Because of this, the most important laws became those that protected the lives of mutants. Examples of this was that performing stem cell research with mutant embryos was prohibited while using altered human embryos was allowed. This is how the racism became quite opposite, in that Sapiens were the outcasts in society and mutants held all great positions of power. Though some humans were given privileges the majority of Sapiens were rejected by society.

House of M

This reality is first made known to residents of Earth-616 when the X-Men and Avengers plot to kill Wanda Maximoff because of the dangers of her insanity. So it is that back at Genosha, the Maximoff family unites (Magneto, Quicksilver and the Scarlet Witch).

So the heroes return to Genosha to find all of them missing and slowly, one by one, they are all engulfed by a white light...and transported to the "House of M" reality, officially known as Earth-58163.

It seems in this reality, Wanda has granted everyone their desires so that they can be truly happy. And none of the Earth-616 natives remember this, except for Wolverine of course who has his memory completely restored.

The key to saving all those who have fallen prey to Wanda is the mysterious young girl, Layla Miller who remembers everything and has the power to restore one's memory of their Earth-616 life.

So after she "awakens" more than a dozen heroes who are ready to bring the fight to Magneto, who at that moment ignores his daughter Polaris while mourning the loss of his good friend, Professor X.

While the team flies to Genosha in a helicarrier, they talk amongst each other about the upcoming fight and Jessica Drew brings up the fact that since they've all been given what they want, shouldn't they be content...but Wolverine ignores the thought.

The team arrives at Genosha and a battle ensues between the House of Magnus and the mutant royalty that has come to Genosha to celebrate the triumph of Homo Superior versus the "awakened" heroes.

As the battle continues it seems that everyone is to meet their end here, but when Magneto learns the truth of the matter (that it was Pietro who had Wanda create this fantasy world) he began to unleash his fury upon everyone, especially his son.

Quicksilver is beaten to a bleeding mass, but the Scarlet Witch comes to his rescue and heals his body and becomes angry with her father and her next few words change Earth-616 so drastically that it would likely be best if it could be undone. She said, "We're freaks, mutants...you chose this over us and you ruined us...", then she whispers the words that caused M-Day, "Daddy...No More Mutants."

And Earth-58163 disappears yet again in a flash of white...